var $ = require('../internals/export');
var shared = require('../internals/shared');
var getBuiltIn = require('../internals/get-built-in');
var uncurryThis = require('../internals/function-uncurry-this');
var isSymbol = require('../internals/is-symbol');
var wellKnownSymbol = require('../internals/well-known-symbol');

var Symbol = getBuiltIn('Symbol');
var $isWellKnown = Symbol.isWellKnown;
var getOwnPropertyNames = getBuiltIn('Object', 'getOwnPropertyNames');
var thisSymbolValue = uncurryThis(Symbol.prototype.valueOf);
var WellKnownSymbolsStore = shared('wks');

for (var i = 0, symbolKeys = getOwnPropertyNames(Symbol), symbolKeysLength = symbolKeys.length; i < symbolKeysLength; i++) {
  // some old engines throws on access to some keys like `arguments` or `caller`
  try {
    var symbolKey = symbolKeys[i];
    if (isSymbol(Symbol[symbolKey])) wellKnownSymbol(symbolKey);
  } catch (error) { /* empty */ }
}

// `Symbol.isWellKnown` method
// https://tc39.es/proposal-symbol-predicates/#sec-symbol-iswellknown
// We should patch it for newly added well-known symbols. If it's not required, this module just will not be injected
$({ target: 'Symbol', stat: true, forced: true }, {
  isWellKnown: function isWellKnown(value) {
    if ($isWellKnown && $isWellKnown(value)) return true;
    try {
      var symbol = thisSymbolValue(value);
      for (var j = 0, keys = getOwnPropertyNames(WellKnownSymbolsStore), keysLength = keys.length; j < keysLength; j++) {
        if (WellKnownSymbolsStore[keys[j]] == symbol) return true;
      }
    } catch (error) { /* empty */ }
    return false;
  }
});